On Thu, Aug 23, 2012 at 12:06 PM, Gen Liu <[email protected]> wrote: > > > On 8/18/12 12:33 PM, "Stack" <[email protected]> wrote: > >>On Fri, Aug 17, 2012 at 4:42 PM, Gen Liu <[email protected]> wrote: >>> I assume block cache store compressed data, >> >>Generally its not, not unless you use block encoding. > Can you be more specific on this? Are you talking about > https://issues.apache.org/jira/browse/HBASE-4218 > So this is only available in 0.94 then? Thanks. >> >>> one block can hold 6 rows, but in random read, maybe 1 row is ever >>>accessed, 5/6 of the cache space is wasted. >>> Is there a better way of caching for random read. Lower the block size >>>to 32k or even 16k might be a choice. >>> >> >>We don't seem to list this as an option in this section, >>http://hbase.apache.org/book.html#perf.reading, but yes, if lots of >>random reads, smaller block cache could make a difference. >>
See release note in https://issues.apache.org/jira/browse/HBASE-4218 St.Ack
